Research progress of coronary artery occlusion associated with transcatheter aortic valve implantation / 中国胸心血管外科临床杂志

@#Transcatheter aortic valve implantation (TAVI) has become the main treatment for elderly patients with middle and high risk aortic stenosis. However, coronary artery occlusion (CAO) related to TAVI is a very serious complication, which often leads to poor prognosis. Therefore, active preoperative prevention is particularly important. Preoperative computed tomography evaluation, bioprosthetic or native aortic scallop intentional laceration and chimney stent implantation technology can prevent TAVI-related coronary orifice obstruction. Ensuring commissural alignment during operation can reduce the occurrence of coronary occlusion, but its long-term prognosis needs further study. In addition, percutaneous coronary intervention is the main treatment, but there are problems such as difficult coronary access after TAVI. This article summarized the research progress in the mechanism, prevention and treatment of CAO related to TAVI.

The clinical application of a new interventional therapy for acute left main coronary artery occlusion / 介入放射学杂志

Objective To investigate the curative effect of a new interventional therapy for acute left main coronary artery occlusion.Methods The clinical data of a total of 58 patients with acute left main coronary artery occlusion,who were admitted to authors' hospital during the period from May 2003 to October 2016 to receive treatment,were retrospectively analyzed.Among the 58 patients,14 patients underwent traditional percutaneous coronary intervention (PCI group),and 44 patients (combination treatment group) received small balloon expansion first,and subsequent stent implantation was carried out in 30-40 min after the coronary blood flow restored to grade Ⅲ of TIMI classification.Results In PCI group,8 patients died,the mortality was 57.1％(8/14).In combination treatment group,only 3 patients died,the mortality was 6.8％ (3/44).Conclusion For the treatment of acute left main coronary artery occlusion,combination use of small balloon expansion and subsequent stent implantation is a safe and effective therapy with lower mortality.

Simultaneous acute myocardial infarction in two coronary arteries / 대한내과학회지

The simultaneous presentation of acute myocardial infarction (AMI) in the right and left coronary arteriesis rare. Diabetes mellitus (DM), thrombus due to multivessel spasm, AMI with hypercoagulation,and hypoperfusion of other coronary arteries after an AMI may cause the simultaneous occurrence of right and left coronary artery infarctions. If emergency coronary revascularization (percutaneous coronary intervention, thrombolysis, and coronary artery bypass surgery) is not performed immediately, the mortality rate is very high due to the development of cardiogenic shock and ventricular arrhythmia. Here, we report a number of cases involving the simultaneous development of AMIin two coronary arteries and discuss the importance of rapid revascularization.

Primary PCI for acute myocardial infarction caused by acute left main coronary artery occlusion / 中国实用内科杂志

Objective To study mortality of acute myocardial infarction caused by acute left main coronary artery occlusion.The objectives of this analysis were to determine the effect of primary PCI and the impact of cardiogenic shock on acute myocardial infarction caused by acute left main coronary artery occlusion.Methods From 1999 to 2005,of 752 consecutive patients with acute myocardial infarction,16 patients had acute left main coronary artery occlusion with TIMI flow≤2.All patients were given primary PCI.Results Of these 16 patients,9(56.25%)died in hospital,and 7(43.75%)discharged.In the survival group reperfusion was successful in 100% of patients,as opposed to 44.44% in the mortality group(P=0.019).Cardiogenic shock was overt in 12(75.00%)patients,42.86% of the survival group and 100% of the mortality group(P=0.020).Shock patients had higher in-hospital mortality than stable patients(75 % vs 0%,odds=4.0,95%CI 1.50~10.66,P=0.019).Conclusion Patients presenting with AMI caused by acute left main coronary artery occlusion and cardiogenic shock have poor survival regardless of primary PCI.Nevertheless,primary PCI is a feasible and effective procedure,and it may save lives in this clinical setting.

Mechanical Obstruction of Right Coronary Artery during Aortic Valve Replacement / 대한흉부외과학회지

Although the incidence is very low, acute mechanical obstruction of the right coronary artery may occur as a cause of right ventricular failure during aortic surgery. In a 67-year-old woman with severe aortic regurgitation, acute right ventricular failure was noticed at the end of cardiopulmonary bypass weaning after an aortic valve replacement with a Hancock II 19 mm bioprosthesis. We suspected mechanical obstruction of the right coronary artery and consequent coronary artery bypass graft to the right coronary artery with right internal mammary artery was performed with success in weaning the bypass. On the postoperative 9th day, the right coronary angiogram revealed obstruction at proximal right coronary artery by plaque emboli. We herein report a clinical case in which the acute right ventricular failure occurred due to mechanical obstruction of the right coronary artery was recovered by coronary artery bypass graft to the right coronary artery.

Effects of Thoracic Epidural Anesthesia on Systemic and Myocardial Oxygen Supply/Demand Balance during Coronary Occlusion in Dogs / 대한마취과학회지

BACKGROUND: A thoracic epidural combined with general anesthesia may reduce the oxygen demand of the heart by cardiac sympathetic blockade, but it may also reduce the systemic and cardiac oxygen delivery due to hypoperfusion which is critical to patients with significant coronary lesions. This study was done to investigate the effects of thoracic epidural anesthesia on the systemic and cardiac oxygen supply/demand balance during coronary occlusion in dogs. METHODS: In 10 dogs, the left circumflex coronary artery was occluded, and then thoracic epidural anesthesia was given at the T5-6 or T6-7 level with 5 ml of 0.5% bupivacaine to block T1-T12 through the surgically introduced epidural catheter. Hemodynamic parameters and arterial, mixed venous and coronary sinus blood samples were obtained at baseline and 30 minutes after coronary occlusion. The same parameters were also measured at 30, 60, 90, 120 and 150 minutes after the epidural blockade. An epicardial 2D-echocardiogram was done by a cardiologist at baseline, 30 minutes after occlusion and 1 hour after the epidural blockade. RESULTS: Systemic oxygen delivery (O2 flux) was decreased after epidural anesthesia (p < 0.05), but oxygen consumption (VO2) was maintained throughout the experimental periods. Although the systemic oxygen extraction ratio (O2ER) was not changed, cardiac O2ER was increased at 90, 120 and 150 minutes after epidural anesthesia (p < 0.05). The end-diastolic noncontractile area of the left ventricle was increased, pulmonary capillary wedge pressure was increased 90 minutes after epidural anesthesia and cardiac output was decreased 120 minutes after epidural anesthesia (p < 0.05). CONCLSIONS: In the experimental canine model of coronary occlusion, thoracic epidural anesthesia induces diminished systemic oxygen delivery without deteriorating oxygen supply/demand balance. However, as PsO2 and SsO2 diminished and the noncontractile left ventricular area increased after epidural anesthesia in the setting of acute coronary occlusion, perioperative use of thoracic epidural anesthesia in patients of coronary disease should be done carefully in order not to aggravate myocardial ischemia.

Myocardial Abscess with Coronary Artery Occlusion: One Case Report / 대한흉부외과학회지

Myocardial abscess usually occurs as a complication of infective endocarditis or over-whelming septicemia. Coronary artery occlusion caused by myocardial abscess has been rarely reported. A 61-year-old man presented with fever and chill that developed 6 weeks prior to admission. He had a history of cardiopulmonary resuscitation for ventricular fibrillation and cardiac arrest 4 weeks prior to admission. Echocardiography showed a 3 x 4cm sized mass in the area of the right atrioventricular groove and coronary angiography showed complete occlusion of the proximal right coronary artery. Under the diagnosis of myocardial infarction complicating myocardial abscess, debridement of abscess and coronary artery bypass grafting with right internal mammary artery to distal right coronary artery was performed. Culture from the abscess cavity demonstrated Salmonella arizona.

Effect of Coronary Artery Occlusion and Reperfusion on Signal Average Electrocardiography in Cats

BACKGROUND: Recently, a lower incidence of late potentials has been reported in patients with acute myocardial infarction after successful thrombolysis when compared with conventionally treated patients. In another recent study, however, no significant effect of thrombolytic therapy on any abnormal signal average electrocardiography was found at 13 days after acute myocardial infarction. The present study was designed to determine the prognostic significance of the signal average electrocardiography and to evaluate the possible value of this technique as a noninvasive tool for monitoring of coronary occlusion and reperfusion. METHODS: Signal averaging was performed by using a signal average electrocardiography with bidirectional filterings before coronary artery occlusion, at 5 minutes after coronary occlusion and on reperfusion in 20 cats. Three of them died due to malignant ventricular arrhythmia during reperfusion. In all cats, approximately 250 beats were averaged. All data were analysed at filter frequency 25 to 250Hz, 40 to 250Hz and 80 to 250Hz. The following quantitative high resolutional electrocardiographic variables were calculated by computer : 1) filtered total QRS duration, 2) duration of HFLA(high frequency low amplitude) signals under 40uV, 3) RMS voltage of terminal 40ms, 4) mean Voltage of terminal 40ms, 5) average noise voltage. RESULTS: At the filter frequency of 40 to 250Hz and 80 to 250Hz, the filtered QRS duration and duration of HFLA signals 40uV were significantly prolonged at 5 minutes after coronary artery occlusion than before coronary occlusion(p<0.01). At the filter frequency of 40 to 250Hz and 80 to 250Hz, the RMS voltage(terminal 40ms) and mean voltage(terminal 40ms) were significantly prolonged at 5 minutes after coronary artery occlusion than before coronary occlusion(p<0.01, p<0.01 respectively). At the filter frequency of 80 to 250Hz, the filtered QRS duration and at the filter frequency of 25-250Hz, the duration of HFLA signals at 40uV were significantly shortened during reperfusion than at 5 minutes after coronary artery occlusion(p<0.01, p<0.05 respectively). At the filter frequency of 40 to 250Hz and 80 to 250Hz, the RMS voltage(terminal 40ms) and mean Voltage(terminal 40ms) were significantly shortened during reperfusion than at 5 minutes after coronary artery occlusion(p<0.01, p<0.01 respectively). There was no significant change of the filtered QRS duration, duration of HFLA signals 40uV,RMS voltage(terminal 40ms) and mean Voltage(terminal 40ms) after reperfusion compared with those of control at the filter frequency of 25 to 250Hz, 40 to 250Hz and 80 to 250Hz respectively. CONCLUSION: These results suggest that the signal average electrocardiography could be a valuable tool for monitoring the state of coronary artery occlusion and reperfusion.

A Study on the Changes in Left Ventricular Function by Experimental Coronary Artery Occlusion and Reperfusion

In order to observe the changes in left ventricular function during coronary artery occlusion and reperfusion, left anterior descending (LAD) coronary arteries in the anesthetized dogs were occluded for 1 hour and then reperfused for 4 hours. Hemodynamic indexes of global systolic and diastolic function and regional wall thickness changes as a regional contractile index were measured during occlusion and reperfusion. The results were as follows; 1) Indexes of global systolic function (left ventricular peak systolic pressure, peak positive dP/dt) and global diastolic function (peak negative dP/dt, time constant, left ventricular end-diastolic pressure) showed deterioration in early occlusion period (10-30 minutes) but gradually improved even if coronary occlusion persisted. Reperfusion did not induce significant changes except that peak positive dP/dt transiently deteriorated 30 minutes after reperfusion and left ventricular end-diastolic pressure decreased 1.5-2 hours after reperfusion. 2) Indexed of regional function (i.e, end-diastolic thickness and % systolic thickening of anterior left ventricular wall) deteriorated by 10 minutes' occlusion which persisted during the entire occlusion period. Reperfusion induced no significant improvement in regional contractile function compared with occlusion 60 minutes' data, which suggested reperfusion for 4 hours after 1 hour's LAD occlusion may be insufficient for the ischemic region to recover its contractility. 3) Reperfusion arrhythmia (ventricular tachycardia) was noted in most (6/9) of the dogs, one of which deteriorated into ventricular fibrillation and the others spontaneously converted to normal sinus rhythm.

COMPARISON STUDY OF EFFECTS OF CALCULUS AND MOSCHUS TOTAL EXTRACT AND HYDROCORTISONE ON MYOCARDIAL FUNCTION IN DOGS FOLLOWING CORONARY ARTERY OCCLUSION / 中国药理学通报

This study was aimed to compare the anti-inflammatory calculus bovis and moschus ( C + M) with the typical steroid hydrocortisone (H) in their effects on regional ischemic myocardium. 22 anesthetized dogs were studied by the mercnry-in-Silastic length gauge and divided into Saline (S) ( n= 7 ) , C + M ( n= 8 ) and H ( n=7 ) groups. Within 3 h after occlusion of left anterior descending coronary artery (LAD), the phasic segmental length ( ASL) was reduced significantly in the II groups, indicating that regional myocardial function was improved.The amplitude of VSL in the (C + M) group, however, was not obviously changed at 1,2 and 3 h after occlusion LAD. This was identical with that of the Saline group. These results show that though C + M and H were both anti-inflammatory agents in peripheral tissues as mentioned in previous reports, C + M had no steroid effect in ischemic myocardium.

Effects of Qi-tonics and Blood-activating Decoction on Acute Myocardial Infarction and Reperfusion Injury in Anaesthetized Rats / 第二军医大学学报

The effects of qi-tonics and blood-activating decoction on acute myocardial infarction and ischemia-reperfusion induced arrhythmias were studied in anaesthetized open chest SD rats. Three days before coronary artery occlusion, the qi-tonics and blood-activating decoction was perfused into the stomach of the rats in the experimental group (10 ml/kg weight) once a day, and 4d later, the coronary artery was occluded in anaesthetized open chest rats. The results demonstrated that qi-tonics and blood-activating decoction could reduce significantly the incidence and severity of arrhythmias caused by myocardial infarction and ischemia-reperfusion. The qi-tonics and blood-activating decoction could decrease the amount of the superoxide anion radicals (O2-) produced in the alkaline dimethyl sulfoxide (DMSO) system measured by electron paramagnetic resonance (EPR) at low temperature. The effect of qi-tonics and blood-activating decoction on O2-may be one of the mechanisms for its antiarrhythmic effect during reperfusion.